The present disclosure relates generally to the field of biological signal measurement. More particularly, the present disclosure relates to systems of and methods for measuring impedance associated with electrodes used in measuring biological signals.
Long term monitoring of biological signals, such as electrocardiogram (ECG) signals, presents unique challenges in maintenance of signal quality. The quality of the electrode contact with a patient can and often does deteriorate over time. For example, a gel or other conductive substance used to effect electrical contact to the patient can dry out, causing the conductive properties to be affected. When the quality of the electrode contact deteriorates, the reliability/accuracy of the biological signal measurement is diminished. There is a need for a system for monitoring the quality of electrode contact that allows for continued monitoring after placement of electrodes without interfering with measurement of the biological signal.